Transcript for Russian Authorities Turn Over Wire Taps of Tsarnaev Family

Intercepted between the mother and one of her son's long before the bombings. This is we learn more about a possible turning point for the older brother while here in America ABC's -- -- -- -- is in Boston again tonight. The wiretap has the world asking questions. What did the Russians here in those 2011. Recorded phone calls between Tamil and -- and I and his mum back in Russia. US officials learned of the cold only last week. And they are now focused for invest. The gators I do believe she comes into the United States that. She will be detained for question. So I think there is there a connection while the mother was added to a US terror watch less than 2011. -- -- may have been going through changes of his own. Friends reportedly say after two golden gloves titles. He had abandoned his dream of competitive boxing after he was barred from the national championships. Because of his immigration status a pivotal moment they third. Turning him toward Islam. And more than a year later came that six month trip to Russia. The real test of -- whether he was radicalized -- not -- he was radicalized -- Russia. And we have to do a lot of investigation in Russia because when he went over to Russia and then came back things changed. For now camel and body -- unclaimed in Boston far -- -- while their heads that he'd fly to the US but we're now told he's too sick to travel. Son Joseph -- remains in a federal prison medical -- outside of Boston. Alone in a 100 square foot -- -- -- is no longer talking to investigators. But on ABC's. This week the chairman of the House Intelligence Committee told George Stephanopoulos. Agents or tracking other leads. There are still persons of interest in the United States that the FBI would like to have conversations -- Right now investigators want to know what -- a master bomb maker someone training these two Brothers. That person may be overseas statement.

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